This invention relates to colloidal antimony pentoxide powders useful as flame retardants and which are dispersible to colloidal size in polar solvents.
Products of this nature are known in the art. For example, Nyacol Products, Inc., assignee of this invention manufactures and sells under the trade designation: ADP 494 a polar solvent-dispersible colloidal antimony pentoxide powder which may contain on the order of 71-75% by weight antimony pentoxide and in which the colloidal particles are hydrated pentoxide. In general, these agglomerates, which are on the order of 10-40 microns in diameter before dispersion, form dispersions in polar solvents of particles predominantly on the order of 0.03 micron.
The aforementioned colloidal antimony pentoxide powder may be prepared by admixing colloidal antimony pentoxide, phosphoric acid and a suitable ethoxylated fatty acid amine; and thereafter drying in air to an adsorbed moisture content of no greater than three percent.
While the foregoing commercially available product has enjoyed commercial success and is entirely satisfactory for most contemplated uses, it nevertheless possesses less than optimum dispersibility in polar solvents.
Stated simply, the task of this invention is to provide colloidal antimony pentoxide powders of the foregoing general description and which have improved dispersibility in polar solvents.